Sound waves probably pass through the mouth, resonate in the lungs and are
transmitted through soft tissues to the inner ear, according to Hetherington. He
says that, as many fishes use their air bladders in the same way, “it’s most
likely this was the original hearing mechanism on land”.

A VIRAL protein that punches holes in bacteria could help scientists to
devise new antibiotics.

Bacteria infected with a virus called a filamentous phage live normally but
occasionally belch out new copies of the phage. Now Denise Marciano and her
colleagues at Rockefeller University in New York have found that a viral protein
called pIV forms a pore in the bacterium’s cell membrane to let the phages out
(Science, vol 284, p 1516).

A mutant version of pIV makes cell membranes leaky by staying open too long,
the researchers discovered. They suspect that harmful bacteria release toxins
through similar channels. If so, compounds that pry these channels open could
kill bacteria by upsetting conditions inside them.

THE poles of Jupiter’s moon Europa stay surprisingly warm at night, according
to data from the Galileo spacecraft.

John Spencer of Lowell Observatory in Flagstaff, Arizona, and his colleagues
analysed thermal radiation coming from the moon, which may harbour a liquid
ocean beneath its icy surface. The researchers found that night-time heat flow
at the poles was 1 watt per square metre higher than would be expected from
tidal heating by Jupiter’s gravity (Science, vol 284, p 1514).

The source of the extra heat is unknown. Spencer doubts that putative
volcanic vents under the ice are responsible, but says “small local variations
in temperature could conceivably be due to [volcanic] hotspots”. These areas
could make promising targets for future missions, he suggests.

TENERIFE was a violent place before the Spanish arrived, a study of the
skulls of its inhabitants has found.

Conrado Rodríguez-Martín of the Canaries Institute of
Palaeopathology and Bioanthropology in Santa Cruz de Tenerife examined over 400
skulls pre-dating the Spanish invasion in 1496. Around 10 per cent of the skulls
showed circular cranial fractures, an injury rarely found among archaeological
human skeletons. The fractures were most common among males in their twenties
and early thirties (Journal of Paleopathology, vol 9, p 91).

The pre-Hispanic inhabitants of the Canaries, the Guanches, fought with
weapons similar to an Argentinean bola (two or more heavy balls attached to a
cord). Over 80 per cent of the fractures show clear signs of healing, says
Rodríguez-Martín, though he suspects brain damage may have
resulted from the injuries.

MELATONIN, widely taken as an antioxidant and to combat jet lag, transforms
inside the body into two compounds similar to brain-signalling chemicals.

Giuseppe Squadrito and his colleagues at Louisiana State University in Baton
Rouge have found that carbonate and nitrogen dioxide radicals, which are
constantly formed in the body, react with melatonin to form two compounds that
resemble neurotransmitters.

Although the function of the neurotransmitters is unknown, Squadrito believes
the melatonin derivatives could affect mood, sleep patterns and sex drive. “It’s
speculative, but they have a structure similar to [neurotransmitters] known to
have bioreactivity,” he says. The results will appear in Chemical Research in
Toxicology.

DIAMONDS may be more plentiful than anyone dared imagine, say scientists in
France.

If they have not been washed into riverbeds, the precious stones are usually
found in volcanic rocks associated with old continental crust. But Nicholas
Arndt of the University of Grenoble and his colleagues have found diamonds in
French Guiana among rocks that were originally part of an oceanic island arc
(Nature, vol 399, p 456).

The geologists suggest that mining companies might profit from expanding the
range of places where they look for the gems. The rocks where the diamonds were
found must have originated more than 250 kilometres inside the Earth, where
pressures are high enough to squeeze carbon into diamonds.